1. Field of the Invention
The present invention relates to a head assembly and a magnetic disk drive having the head assembly.
2. Description of the Related Art
As magnetic disk drives have become smaller in size and greater in data storage density in recent years, the distance that a head slider floats off the magnetic disk is so reduced that there has been a demand for a magnetic disk drive in which a head slider floats off the magnetic disk a very small distance or is held in contact with the magnetic disk for contact recording/reproduction. Conventional magnetic induction heads suffer a degraded reproduction output capability if the peripheral speed, i.e., the relative speed between the head and the magnetic disk, is lowered due to a reduced magnetic disk diameter. It has been desired in the art to develop a magnetoresistive head (hereinafter referred to as an MR head) whose reproduction output capability does not depend on the peripheral speed and which is capable of producing a high reproduced output at low peripheral speeds.
The MR head operates by supplying a constant sense current to a magnetoresistive element (MR element), converting a change in the magnitude of a signal magnetic field leaking from a recording track on a recording medium into a change in the resistance of the MR head, and reproducing information recorded on the recording medium as a voltage change. The MR head generally has the MR element formed integrally with a head slider according to a thin-film fabrication process. The slider has a data-writing coil and is mounted by bonding or the like on the tip end of a suspension which is made of stainless steel.
Leads which connect the MR element and the data-writing coil to a recording/reproducing circuit of the magnetic disk drive are constructed as a copper pattern printed on the suspension. When the suspension is mounted on the tip end of an actuator arm, the MR element and the data-writing coil are electrically connected to the recording/reproducing circuit through a flexible printed circuit (FPC) or the like.
With a suspension which supports a conventional MR head slider, a pair of leads connected to terminals of the MR element or these leads and a ground line connected to a magnetic shield of the MR element are electrically disconnected from each other. Therefore, when the worker who is electrostatically charged handles the suspension with the MR head slider supported thereon or carries the suspension in an easily electrostatically chargeable casing made of synthetic resin or the like, an excessive current due to an electrostatic charge tends to flow into the MR element, damaging the MR element, or an electrostatic charge between the MR element and the magnetic shield is liable to be discharged, burning out the MR element.